Invertebrates first appeared on Earth during which time period?
A. Mesozoic
B. Paleozoic
C. Cenozoic
D. Precambrian
E. Cambrian
2007-08-02 02:30:39 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Earth Sciences & Geology
E, Cambrian
2007-08-02 02:47:42 · answer #1 · answered by ♥Anonymous♥ 2 · 0⤊ 0⤋
The first invertebrate fossils are from the Cambrian. There seems to've been a long period of strong erosion in the Pre-Cambrian that would've destroyed any fossils from that era or eon. This erosion may've lasted 100,000,000 years. What caused such a thing?
2007-08-02 02:39:19 · answer #2 · answered by miyuki & kyojin 7 · 0⤊ 1⤋
Soft bodied invertebrates are well-known from the late precambrian (try a search for the Ediacara fauna if you want more details), so the answer in D.
2007-08-02 05:40:53 · answer #3 · answered by Andrew 5 · 2⤊ 0⤋
Precambrian. Without question.
2007-08-02 11:05:23 · answer #4 · answered by Anonymous · 0⤊ 0⤋